Review of Operating Systems

This page has been superceded by the project Wiki OS Review area.

Original Free OS Projects

  • Anders Gavare's Yoctix is an emerging operating system very much inspired by BSD Unix, but implemented fully from scratch and following its own path. Anders' goal is to educate himself and to come up with a full documentation, written as he progresses, of how to write such a thing. After only 6 months of work, Yoctix boots /sbin/init. Even cutting corners as he did, this is very impressive. Definitely worth a look.

    Free OS projects in early stages of development

  • "Joker" Josh MacDonald's OSDEV
  • OS-DeViLs project (with an hardware independence page here), is a federation of people hacking new OSes, so they can debate ideas,
  • Michael Gerhards' UniqueOS plans to make an OS based on no fixed data structures, using a technique called tag items, borrowed from AmigaOS. More information and documentation can be found on the site. A few sources can be downloaded.
  • Jascha Wetzel's XOS aims at being an object-oriented, distributed, preemptively multitasked/threaded, message-passing based system. While this would sound like pretty standard marketroid talk, the site contains very interesting, detailed and clear documentation about what the author has in mind, an object-oriented microkernel where every part of the system does one thing and does it well, without any of the other parts knowing the details; a definite plus for scalability and future expansion. The author also cares to define the concepts he uses, so have a look at it even if you don't do C++ in your sleep. The actual implementation hasn't started yet, but definitely a spot to watch.

    Apparently dead OS projects

    The following OS projects seem to be dead, as in not having been upgraded for years. However, they are still worth mentioning, as learning tools, and also in the hope that maybe someone will want to pick up the work where it stopped.

    Educational OSes

    These are instructional OSes developed and used in some Universities for their OS courses. They are freely available, and have some docs, too. In portable C, unless stated otherwise.

    Popular Commercial OSes and their clones

    Original contributions from Commercial systems

    Operating system for embedded devices

    As embedded systems (PDAs, cellphones, point-of-sale devices, VCRs, industrial robot control, or even your toaster) become more complex hardware-wise with every generation, and more features are put into them by the day, applications they run require more and more to run on actual operating system code in order to keep the development time reasonable.

    The good:

  • Nexus' coniX small romable embedded operating system for ARM processors.
  • Sun's JavaOS (with a more technical page at JavaSoft) was a standalone virtual machine not running on top of any other OS; mainly targetted at embedded systems. Proprietary project dropped.
  • Palm Computing's PalmOS for the Palm Pilot and soon a flurry of other mobile products. Currently the leader OS for PDAs, has many applications and supporting companies.
  • Microsoft's attempts at fitting a large unstable desktop-PC operating system, with a hammer, into the stringent requirements of embedded systems are here: Windows CE (which is about to lose its 'CE' part so as to confuse people a bit more) and their latest monster, Windows NT Embedded 4.0.

    Commercial Unices and beyond

    Lots of commercial vendors base their system on the Unix family of design, as standardized in POSIX.
    The existence of free Unix systems like the great Linux forces them to find justifications for charging so much for systems that were so bad; hence, recently, significant OS research has been done by commercial companies, even though the benefit for users and developers is not obvious, as "protected" research is by definition not beneficial to people.

    DOS-class systems and extensions

    Because DOS has been such a phenomenon in OS history, that it ought to have a place here, despite its absolute nullity (the only service of it that is used rather than worked around is the filesystem, which is the worst piece of junk ever implemented).

    Losedoze-class systems

    The same company consistently produces the worst wimpy OS, hence this section...

    OS Related Pointers

    More netsurfing

    To Do on this page